The invention relates to couplings in general, and more particularly to improvements in couplings which can be utilized to establish a fluidtight and separable connection between a nipple at one end of a metallic or plastic pipe and an end portion of a second tubular component, particularly the end portion of a flexible elastic hose. Still more particularly, the invention relates to improvements in couplings of the type wherein a sleeve-like tubular coupling member can extend into the end portion of the hose and is provided with one or more flexible coupling elements which can engage a retainer at the exterior of the nipple.
Commonly owned U.S. Pat. No. 4,775,173 to Sauer discloses a hose coupling wherein the tubular coupling member is made of a plastic material and extends into the end portion of the hose as well as into the nipple. The tubular member has external coupling elements in the form of hooks which can engage an external rib of the nipple in assembled condition of the patented coupling. The coupling elements are integral with a median portion of the coupling member. A tubular clamping member is placed around the end portion of the hose to sealingly engage such end portion and to maintain it in engagement with the respective portion of the coupling member.
A drawback of the patented coupling is that the tubular coupling member is complex and expensive as well as the coupling member must be made of a plastic material because it would cost too much to make it from a metallic substance. In view of the fact that the tubular portion of the coupling member is integral with rather complex elastically deformable coupling elements, it is necessary to design special plastic processing machines which are capable of producing such coupling members at an acceptable cost. Moreover, the outwardly extending coupling elements contribute to the bulk of the coupling member and of the entire coupling.